Pallet car and bottom board installation for handling molds

ABSTRACT

Apparatus and method for an automatic pallet car loading and return mechanism, and a bottom board loading and return mechanism of a metal casting system having rail means, elevator means and return conveyor means for the bottom boards; rail means, return means and elevator means for the pallet cars, and controlling means for directing the movements of both bottom boards and pallet cars.

United States Patent [72] lriventor Jesse M. Turner [56] References Cit d APPLNQ 4 2,274,842 3/1942 McCann 198/24 [221 PM "M968 3 276 609 10/1966 Kile 214/16 45] Patented Jan. 12, 1971 l 3,315,785 4/1967 Shlffer 198/85 Primary Examiner-Gerald M. Forlenza Assistant Examiner-Raymond B. Johnson Attomey-Newton, Hopkins and Ormsby [.54] PALLET CAR AND BOTTOM BOARD M lNsTA LLAn0Nol;,.H1ANDLING MOLDS ABSTRACT: Apparatus and method for an automatic pallet 11 Chums 5 Drawmg car loading and return mechanism, and a bottom board load- [52] [1.8. CI 198/85, ing and return mechanism of a metal casting system having rail 214/16 means, elevator means and return conveyor means for the bot- [51] Int. Cl 865g 37/00 torn boards; rail means, return means and elevator means for [50] Field of Search 214/ 16B, the pallet cars, and controlling means for directing the movements of both bottom boards and pallet cars.

PAYENTEU JAN 1 215m 1 3554.358

SHEET 2 BF 4 PATENTED JAN! 2 ram SHEET 3 UP 4 PATENTED JAN 1 2 19?:

SHEET 0F 4 PALLET CAR AND BOTTOM BOARD INSTALLATION FOR HANDLING MOLDS With the admission to this country of crude metals and crude metal castings from outside this country where they are produced at a much lower cost than in this country, the metal industriesare seeking means in order to compete economically with these foreign imports. In the casting or metal foundry industry there is a serious problem of efficiently utilizing manpower. In the prior art, so many of the movements involved in casting metals require a considerable amount of manual operation. Thus, the use of many workers results in an increase in the cost of metal castings to the point where the cost of sameis above that of foreignimports. Therefore, the metal industries as a whole in this country are turning more and more to trying various systems which will of course reduce the individual per unit cost of metal and castings thus produced:

It is therefore the primary object of this invention to provide a method and apparatus which is fully automatic for the casting of metals.

Another object of this invention is to provide a metal casting apparatus system which can be successfully operated by one operator.

A further object of this invention is to provide an apparatus and method for placing a mold on a bottom board and automatically loading a pallet car with the occupied bottom boards.

A still further object of this invention is to provide a method and apparatus for an automatic return of these bottom boards to their loading area once the casing operation has been completed.

It is also an object of the present invention to provide a method and apparatus for an automatic pallet car loading means, and return means for the pallet car to the loading or working area.

' Other objects and advantages of the presentinvention will become apparent from the following detailed description and drawings;

FIG. 1. represents diagrammatically, in perspective, the whole of the automatic installation for the continuous fabrication of sand molds, casting of the molds and a return to the working area of both the pallet cars and the bottom boards;

FIG. 2 is a front view of the automatic pallet car loading, bottom board loading, pallet car return and bottom board return apparatus;

FIG. 3is a top view of the automatic installation;

FIG. 4 is a side view, partially in section, of the elevator used in returning the empty pallet 'car to its original loading position; and

FIG. 5 is a side view, partially in section, of the elevator used in returning the pallet cars to their loading area, showing the elevator in its unloading position.

Referring now to the drawings in detail, in which like numbers represent the same parts in the several drawings, track or rail assembly 1 for moving pallet cars loaded with molds on bottom boards from the loading area to the metal-pouring area, the cooling area to the shake out area and a return of the empty pallet cars to the mold-loadingarea. Tracks 2, 3, 4, and 5 are set at approximately 2 slope so the pallet cars will move forward and return by gravity. This figure discloses two lines or track assemblies but it will be understood that more than two track assemblies or lines may be used in the present invention. Rails 6, 7, 8, and 9 are the return rails for empty pallet cars when they leave the shakeout area and return to the loading area. These rails are at approximately a 2 slope so gravity will return the pallet cars to the loading area. At the forward end of these rails 2, 3, 4, and 5, at point A the forward end of these rails are cut away so that pallet cars may discharge their load of cooled molds by dropping the end pieces B in a downward counterclockwise direction, pivoting around A. Thus, when the molds have been removed from the pallet car, ends B return to an upright position level with the rails and then the end points A of the rails drop downwardly in a clockwise direction so that the pallet car wheels will engage return rails 6, 7, 8, and 9 and return the pallet cars which are empty to their loading area. The entire conveyor system of this invention is supported within vertical beams 16, said beams 16 being tied together by horizontal beams 19 and 22.

The loading area as well as the automatic bottom board loading and return assembly together with the loading of pallet cars and return of same, assembly 10 has a conventional sand mold pressing unit 11 adjacent thereto. The bottom board 21 when empty and not loaded with molds are returned to bottom board stacker l2, Molds 20 are pressed in the mold-pressing unit 11 and are pushed onto a bottom board 21 which has been ejected out of the bottom of the stack of bottom boards at 12. There is a conventional hydraulic cylinder and piston 14 which ejects the bottom board onto its loading position with the mold. A conventional automatic molding machine, such as the Beardsley and Piper model BSM 2016, pushes out or produces as many as three molds per minute and bottom boards must be fed to the machine at the rate of three per minute which utilizes quite a bit of manpower. As each mold is pushed forward, a bottom board is there to receive same. The thus loaded bottom board moves forward over rollers 17 which are supported by beams 18 and 23. This roller conveyor generally will support three loaded bottom boards with molds. As each mold is produced and pushed forward onto a bottom board at 15, and then bottom board ejector 14 shoves forward an empty bottom board to receive the next mold, the loaded bottom board moves forward in the direction of the conveyor and is shoved onto pallet car 50.

As successive molds are produced and placed on bottom boards and they in turn move forward onto the pallet car, once five loaded bottom boards are placed on a pallet car, this is its capacity. Then an empty bottom board is inserted into the chain or succession of loaded bottom boards so that roller conveyor 25 in the area it occupies will not have a loaded bottom board on it when the several lines are activated. In other words, in FIG. 2 which discloses two lines and therefore two pallet cars which are loaded with molds, there is an area occupied by rollers 25 which cannot contain a loaded bottom board. Rollers 25 are supported by support beams 26. If only the first pallet car line is used, and the pallet car is fully loaded, five molds on their bottom boards on the car, the last mold will engage electric limit switch 24 which will be more fully described hereinafter.

If, for whatever reason, the first pallet car line is not is use, then the bottom boards loaded with molds are pushed over onto the second pallet car 50 in the second line. Once five mold-loaded bottom boards are on the second pallet car, the last mold will engage both electric limit switches 27 and 28. Switch 27 is for the use of the second pallet car line, leaving the first pallet car line alone. Limit switch 28 is used to activate both the first and second pallet car lines together. Once a pallet car, as shown in FIG. 2, has been placed in this entire assembly it contains five bottom boards. Thus, when these pallet cars 50 are returned from the shakeout area to the conveyor loading area, they have five empty bottom boards on them. Therefore, as the mold-loaded bottom boards are moved from the moldproducing area onto the conveyor system, an empty bottom board is pushed from the end of the last pallet car onto bottom board elevator 30. These bottom boards roll over skate rollers 31 which are supported within elevator 30. When the bottom board has reached the far end of elevator 30, it will engage an electric limit switch 38 which activates a timer, a solenoid, not shown in the drawings, and an air cylinder 62 which raises the elevator car and bottom board upward to the top of the automatic assembly until elevator stop 46 is engaged.

The elevator runs on wheels 32 up groove support 29 until position 34 is reached which is curved inwardly. This tips elevator 30 so that the bottom board rolls forward off of the elevator onto a skate roller bottom board return conveyor. Rollers 36 in this bottom board conveyor are supported by beams 35 which run from elevator end of this automatic assembly to the bottom board stacker 12 end at a slight angle or slope so the boards return by gravity. The beams 35 are supported by cross beams 37 which are attached to upright beams 16 in the assembly. When air cylinder 62 and its piston are activated, the piston retracts into the cylinder and draws elevator 30 up to its unloading position by sprocket chain 41 which runs over sprocket wheel 42 supported by shaft 44 and beam 45. Chain 41 at one end is attached to the piston and at the other end to elevator 30.

A bottom board 21 which is in stacker 12, is ejected onto conveyor rollers 17 with a mold resting upon it. The thus loaded bottom board will move forward onto a pallet car. When the pallet car is full, five bottom boards supporting five molds, the limit switches will release the pallet cars so they will roll forward away from the conveyor assembly, at right angles to the same. Then the molds resting upon the bottom boards which are in turn supported by the pallet car, have a liquid metal poured into them and they move forward to a cooling area, being pushed forward by other pallet cars coming behind them. Once the pallet car with its load of molds and bottom boards reaches the shakeout area, the pallet car is tipped forward and the molds are dumped off of the bottom boards on the pallet car. The pallet car is then tripped forward in a clockwise direction and returns to the loading area, but beneath same. Then an elevator activated by one of the electric limit switches will activate pallet car elevator 52, described hereinafter, and return the pallet car to the original loading area. Thus the pallet car has made a complete round trip and it is now back in its loading position containing five empty bottom boards.

As additional bottom boards with molds resting 'upon them are shoved forward onto the pallet car, the empty bottom boards are shoved from the end of the pallet car onto bottom board return elevator 30, which raises the bottom board above the loading area to a return conveyor and then the bottom board is returned to the bottom boards stacker. The bottom boards have made this complete cycle of loading with a mold, going to the pouring area, the cooling area, the shakeout area, being returned to the loading area, being shoved off ofa pallet car and then returned by way of an overhead return conveyor to the point of origin in the bottom board stacker without being manually touched by any worker.

The pallet cars used in the automatic conveyor and return system of this invention are different from a conventional pallet car. The conventional car has a deck made up of approximately three steel bars. The pallet cars used in this invention have a solid steel deck plate and plate sides 66 bent inwardly at approximately 60. Thus the bottom boards for this automatic system must have 60 sides to fit in the chambered pallet car guides. With these bent sides, when the pallet car is tipped in a counterclockwise direction at the shakeout area, the bottom boards remain within the bed of the car. These pallet cars generally are 85 inches long and hold five bottom boards with sand molds. However, these cars could be shorter or longer and hold more or fewer bottom boards with sand molds. The exact length and holding capacity of the pallet car is not of importance. The ends of the pallet car deck are bent slightly down to prevent hangup of the bottom boards and the ends of the guide rails are bent outward slightly to prevent bottom board hangup.

When the last mold on the second pallet car reaches electric limit switch 28 as shown in FIG. 2, the contact with the switch activates two brake motors, not shown in the drawings. These motors are connected to a shaft which drives two sprocket wheels 59 around which sprocket chain 58 makes a complete circle. These sprocket wheels are supported by a support 60 which is attached to pallet car rail 2 and pallet car rail 4 within the conveyor assembly 10. Dividing chain 58 into two equal lengths are two dogs 61, protruding at 90 to the chain 51. The brake motors activate the sprocket wheels 59 and thus sprocket chain 58 and turn the chain in a clockwise direction so that the top dog 61 takes the place of the bottom dog and the bottom takes the place of the top dog. As pointed out hereinbefore, the pallet car tract 2 is on a 2 slope in this area,

so as soon as the brake motor starts rotating the dogs, the pallet car rolls out forward toward the pouring area. If this does not occur, the second dog engages pallet car 50 on the rear edge and pushes it out. When these dogs have changed places as shown in FIGS. 4 and 5, a mounted limit switch cuts the brake motors off and the dogs stop in exactly the same position as the other dogs, prior to rotation. As pointed out hereinbefore, the electric controls can be set with a selector switch so that the first pallet line may be used singly, or the second pallet line may be singly, or both the first and second lines can be used at the same time. There are brake motors, sprocket wheels and dog assemblies for each pallet our line. As pointed out hereinbefore, more than two pallet car lines may be used in the automatic assembly system of the present invention.

When dogs 61, either allow pallet car 50 to move forward or it is pushed forward on wheels 51, the loaded pallet car with five bottom boards with sand molds move forward over tracts 2, 3, 4, and 5. As pointed out hereinbefore, liquid metal is poured into the molds on the pallet cars as they move forward, and as the pallet cars move away from the pouring area, due to other pallet cars coming up from the rear and pushing them. The hot metals cool within the molds and finally the molds are removed from the bottom boards and pallet car at the shakeout area and then the pallet cars containing empty bottom boards are returned to a station beneath the loading area of the automatic assembly of this invention over tracks 6, 7, 8, and 9.

The returned empty pallet cars beneath the loading area are shown in FIGS. 4 and 5. These pallet cars are returned upwardly to their loading area by pallet car elevator 52. The pallet cars run onto elevator 52 on rail extensions of rails 6, 7, 8, and 9. These rails form a base in the elevator. When the limit switch which activates the brake motors gives the dogs 61 time to complete one cycle, this switch then activates a solenoid valve, not shown, and an air cylinder and piston assembly 40 which by way of sprocket chain 63 raises the elevator containing a return pallet car from the return bottom rails up to the top rails and tilts slightly downwardly so the pallet car will run out onto top rails 2, 3, 4, and 5 where it is stopped by an up wardly projecting dog 61. Thus the empty pallet car containing five bottom boards is in a position to receive additionally five loaded bottom boards supporting molds. Elevator 52 has upwardly extending guide wheels 53, as shown in FIG. 3, on each side of the pallet car elevator 52. When the elevator reaches a forwardly inclined point 55 in metal support beam 16 which supports guide channel 54, the elevator 52 tips forward so that the pallet car rolls out of said elevator.

In order to prevent a returning empty pallet car from rolling off the end of return rails 6, 7, 8, and 9, when elevator 52 is in the discharge position, there is provided a ratchet 67 pivotally mounted at 68 on the inside of each of the return rails. This ratchet supports at each end thereof a stub 69 which extends at right angles to the ratchet itself. For each of the return rails, there is a ratchet 67 provided inside of the rails. These rails raised stubs 69 will prevent an empty pallet car from rolling off of the return rails while the elevator is in its unloading position as shown in FIG. 5. Ratchet 67 is controlled by operating lever 70 which is rigidly fixed at pivot point 68 so that when lever 70moves upward as shown in FIG. 4, the ratchet itself will move in a clockwise direction at its ends with stubs 69 and will allow an empty pallet car to move forward onto the end of the return rails but still prevent the pallet car from rolling off the rails. On the sides of elevator 52 are two metal stub projections 56 and 57 which extend outwardly perpendicular to the sides of elevator 52. Projection stub 56 is at the top of the elevator and projection stub 57 is at the bottom of the elevator. Elevator 52 with an empty pallet car in it, proceeds to rise upwardly and when it is in its discharge position bottom-projecting stub 57 will engage activating lever or bell crank 73 and move it upwardly in a clockwise direction. Lever 73 is pivotally mounted at 75 on support beam 16. Immediate this pivotal point, there is pivotally connected at 74 a push rod 7I which at its other end 76 is pivotally connected to operating lever 70. Thus when the elevator is at its discharge position, as

shown in FIG. 5, ratchet 67 which has been pivoted due to the actions of operating lever 70 and push rod 72 which have been activated by lower projection 57 on the elevator, pivots ratchet 67 in a clockwise direction so that pallet car 50 will be kept from rolling off the end of rail '9 by stub 69. When this occurs, the empty pallet car which has been returned by the elevator is rolled out to its loading position and is retained there by dog 61. I

As elevator 52 is returned to its unloaded position by chain 63 running over sprocket wheels64 and air cylinder which has been reactivated, the air has escaped from the cylinder slowly, top stub projection 56 engages activating lever 73 and pushes it downward in a counterclockwise direction, thus activating push rod 72 downwardly and in a counterclockwise direction which also in turn pushes operating lever 70 downward, which in turn activates ratchet 67 so that its forward end stub 69 no longer prevents the'pallet car from rolling onto the empty elevator, and at the same time the projection stub 69 at its other endprevents any other pallet car from entering into the ratchet control area. Back rail 65 on elevator 52 prevents the pallet car 50 from rolling off the back side of the elevator, once the pallet'car' has rolled onto the elevator. Thus, the pallet car has made a complete cycle from loading area to pouring area, to' cooling area',.to shakeout area, to the pallet car elevator, and backto its original position without being handled by a single individual.

There is a conventional electric control board, not "shown in the drawings, from which one operator may set all the electric limit and time switches to automatic operation, for one pallet car line or for several,or he may set the whole system upon manual operation. This operator controls also, the mold projection assembly 11 which manufactures the molds which are pushed out onto bottom boards. 21 adjacent bottom board stacker 12. Thus if there is some defect in one of the pallet car lines, the operator may inactivate that lin' ebut prbceed to place the other lines in an automatic condition being'activated by the various electric limit and time switches. Further as far as the pallet cars and bottom boards are concerned, their movements are controlled by only one individual. The pouring area, cooling area and shakeout area are not concerned in the present invention and are described only because the pallet cars pass through them.

1. An installation comprising: pallet cars; bottom boards for receiving and supporting molds; conveyor means for pushing said bottom boards-onto said pallet cars while 's'upporting molds thereon, said bottom boards being disposed horizontally in an end to end relationshipyelevation means for raising empty bottom boards above said conveyor means; means for activating said elevation means; holding means for said bottom boards; return means for receiving empty bottom from said elevation means and returning same to said holding means; means supporting said return means in a vertically i 6 spaced relationship relative tosaid conveyor means; means for guiding and pushing pallet cars with bottom boards and mold thereon from a loading area, which is defined by at least a por- 'tion of said last named means, in a transverse direction relative to said conveyor means; pallet car return means for returning said pallet cars and bottom boards to an area adjacent said loading area after the molds have been removed from said bottom boards, said pallet car return means being vertically spaced relative to said loading area; pallet car elevation means for receiving empty pallet cars from said pallet car return means and raising said cars to a position substantially aligned with said loading area; means for activating said pallet car elevation means; means for preventing empty pallet cars from being displaced from said pallet car return means when said pallet car elevation means is not in a position to receive a car from said pallet car return means; means operative associated with said conveyor means for pushing empty bottom boards off said pallet cars, when said pallet cars are returned to said loadinglarea, onto said bottom boards elevating means. 2. The insta latton ofclaim 1 wherein said conveyor means comprises arow of parallel rollers spaced apart and supported by beams.

3. The installation of claim 1 wherein said bottom board elevation means comprises parallel rows of skate rollers spaced apart and supported by an elevator base.

4. The installation of claim 1 wherein said bottom board return means comprises parallel rows of skate rollers spaced apart and supported by beams inclined at a slight slope so the bottom boards will return to their original position by gravity.

5. The installation of claim 1' wherein said holding means comprises a stacker for indexing said bottom boards onto said conveyor means in an end to end relationship.

6. The installation of claim 1 wherein said activating means for the bottom board elevation means comprising a limit switch being activated by contact with the end of an empty bottom board. I

7. The installation of claim 6 wherein said elevation means comprises an elevator moved by an air cylinder and chain assembly.

8. The installation of claim 1 wherein said push out means comprises a time limit switch activating motors which rotate sprocket wheels supporting a chain circle, said chain being divided into two equal parts by two perpendicular projections.

9. The installation of claim 8 wherein said projection moves in a clockwise direction and pushing .said pallet cars forward as well as holding said cars when in position.

10. The installation of claim 1 wherein said pallet car controlling means comprises a ratchet rod with perpendicular end projections, pivotally mounted in the center, said rod being rotated by engagement of projections on the top and bottom of the elevator with a pivotally mounted actuating lever.

11. The installation of claim 1 wherein said pallet car elevation means comprises an elevator actuated by a time limit switch, air cylinders sprocket chains and wheels. 

1. An installation comprising: pallet cars; bottom boards for receiving and supporting molds; conveyor means for pushing said bottom boards onto said pallet cars while supporting molds thereon, said bottom boards being disposed horizontally in an end to end relationship; elevation means for raising empty bottom boards above said conveyor means; means for activating said elevation means; holding means for said bottom boards; return means for receiving empty bottom boards from said elevation means and returning same to said holding means; means supporting said return means in a vertically spaced relationship relative to said conveyor means; means for guiding and pushing pallet cars with bottom boards and mold thereon from a loading area, which is defined by at least a portion of said last named means, in a transverse direction relative to said conveyor means; pallet car return means for returning said pallet cars and bottom boards to an area adjacent said loading area after the molds have been removed from said bottom boards, said pallet car return means being vertically spaced relative to said loading area; pallet car elevation means for receiving empty pallet cars from said pallet car return means and raising said cars to a position substantially aligned with said loading area; means for activating said pallet car elevation means; means for preventing empty pallet cars from being displaced from said pallet car return means when said pallet car elevation means is not in a position to receive a car from said pallet car return means; means operative associated with said conveyor means for pushing empty bottom boards off said pallet cars, when said pallet cars are returned to said loading area, onto said bottom boards elevating means.
 2. The installation of claim 1 wherein said conveyor means comprises a row of parallel rollers spaced apart and supported by beams.
 3. The installation of claim 1 wherein said bottom board elevation means comprises parallel rows of skate rollers spaced apart and supported by an elevator base.
 4. The installation of claim 1 wherein said bottom board return means comprises parallel rows of skate rollers spaced apart and supported by beams inclined at a slight slope so the bottom boards will return to their original position by gravity.
 5. The installation of claim 1 wherein said holding means comprises a stacker for indexing said bottom boards onto said conveyor means in an end to end relationship.
 6. The installation of claim 1 wherein said activating means for the bottom board elevation means comprising a limit switch being activated by contact with the end of an empty bottom board.
 7. The installation of claim 6 wherein said elevation means comprises an elevator moved by an air cylinder and chain assembly.
 8. The installation of claim 1 wherein said push out means comprises a time limit switch activating motors which rotate sprocket wheels supporting a chain circle, said chain being divided into two equal parts by two perpendicular projections.
 9. The installation of claim 8 wherein said projection moves in a clockwise direction and pushing said pallet cars forward as well as holding said cars when in position.
 10. The installation of claim 1 wherein said pallet car controlling means comprises a ratchet rod with perpendicular end projections, pivotally mounted in the center, said rod being rotated by engagement of projections on the top and bottom Of the elevator with a pivotally mounted actuating lever.
 11. The installation of claim 1 wherein said pallet car elevation means comprises an elevator actuated by a time limit switch, air cylinders sprocket chains and wheels. 